Related papers: Ba$_2$phenanthrene is the main component in the Ba…
We present x-ray powder diffraction (XRPD) and neutron diffraction measurements on the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe2As2, Tc = 32K. Below the magnetic transition temperature Tm = 70K, both techniques show an…
Anisotropies of electrical resistivity, upper critical field, London penetration depth and critical currents have been measured in single crystals of the optimally doped iron pnictide superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$, $x$=0.074…
We report the synthesis and characterization of bulk form diluted magnetic semiconductors Ba(Zn1-2xMnxCox)2As2 (0 <= x <= 0.15) with a crystal structure identical to that of 122-type Fe-based superconductors. Mn and Co co-doping into the…
Polycrystalline samples of underdoped (Ba1-xKx)Fe2As2 (x<=0.4) were synthesized and studied by x-ray powder diffraction, magnetic susceptibility, specific heat and 57Fe-Moessbauer-spectroscopy. The structural phase transition from…
We measured the in-plane optical conductivity of a nearly optimally doped (Ba,K)Fe2As2 single crystal with Tc = 39.1 K. Upon entering the superconducting state the optical conductivity below ~20 meV vanishes, strongly suggesting a fully…
A true understanding of the properties of pnictide superconductors require the development of high-quality materials and performing measurements designed to unravel their intrinsic properties and short-range nematic correlations which are…
We report muon spin rotation experiments on the magnetic penetration depth lambda and the temperature dependence of lambda^{-2} in the over-doped Fe-based high-temperature superconductor (Fe-HTS) Ba_{1-x}Rb_ xFe_2As_2 (x = 0.65) studied at…
Single crystals of the optimally doped, moderately and strongly overdoped high temperature superconductor Tl2Ba2CuO6+x (Tl-2201) with Tc=80, 56 and 30K, respectively, have been investigated by polarized Raman scattering. By taking the peak…
The electronic and magnetic properties of a new diluted magnetic semiconductor (DMS) Ba$_{1-x}$K$_{x}$(Zn$_{1-y}$Mn$_{y}$)$_{2}$As$_{2}$, which is isostructural to so-called 122-type Fe-based superconductors, are investigated by x-ray…
The effects of internal chemical pressure on electron doped iron arsenide superconductors are studied in the series Ba(Fe(1-y)Coy)2(As(1-x)Px)2. Combinations of both dopants induce superconductivity also in such areas where only one would…
Optical spectroscopy on single crystals of the new iron arsenide superconductor Ba{0.55}K{0.45}Fe2As2 shows that the infrared spectrum consists of two major components: a strong metallic Drude band and a well separated mid infrared…
Raman spectra are reported for Ba doped fullerides, BaxC60(x=3,4,and 6). The lowest frequency Hg modes split into five components for Ba4C60 and Ba6C60 even at room temperature, allowing us a quantitative analysis based on the…
Two single crystalline samples with the same nominal composition of Rb0.8Fe2Se2 prepared via slightly different precursor routes under the same thermal processing conditions were investigated at ambient and high pressures. One sample was…
Using polarization-resolved electronic Raman scattering we study under-doped, optimally-doped and over-doped Ba$_{1-x}$K$_{x}$Fe$_2$As$_2$ samples in the normal and superconducting states. We show that low-energy nematic fluctuations are…
Large high-quality single crystals of hole-doped iron-based superconductor (Ba$_{1-x}$K$_x$)Fe$_2$As$_2$ were grown over a broad composition range $0.22 \leq x \leq 1$ by inverted temperature gradient method. We found that high soaking…
We investigate the electronic properties and the superconducting gap characteristics of a single crystal of hole-doped 122 Fe-pnictide Ba$_{0.65}$Na$_{0.35}$Fe$_2$As$_2$ by means of specific heat measurements. The specific heat exhibits a…
We report the results of a systematic investigation of the phase diagram of the iron-based superconductor, Ba1-xKxFe2As2, from x = 0 to x = 1.0 using high resolution neutron and x-ray diffraction and magnetization measurements. The…
We have studied the microwave electrodynamics of single crystal iron-based superconductors Ba$_{0.72}$K$_{0.28}$Fe$_2$As$_2$ (hole-doped, $T_\mathrm{c}$ $\approx $30 K) and Ba(Fe$_{0.95}$Co$_{0.05}$)$_2$As$_2$ (electron-doped,…
We have conducted a comprehensive angle-resolved photoemission study on the normal state electronic structure of the Fe-based superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$. We have identified four dispersive bands which cross the Fermi…
We report on doping dependencies of structural parameters and superconducting transition temperatures in the solid solution (Ba1-xKx)Fe2As2. As the main effect of doping on the crystal structure, we find linear decreasing As-Fe-As bond…